Keratoconus and macular and granular corneal dystrophies are potentially blinding diseases. It is believed that pathologic changes in diseased corneas are related to disturbances in connective tissues such as collagens and proteoglycans. The mechanism of these disease processes, however, still remains unclear. Since elucidation is a prerequisite for eventual development in all clinical aspects, we propose in this application to continue our studies of biosynthesis and metabolism of collagen and proteoglycans in diseased corneas. We plan to measure the protein, collagen, and glycosaminoglycan content in individual corneal tissues and to determine the amount and types of collagen and proteoglycan molecules synthesized both in tissue cultures and in explant cultures. Collagen will be separated by salt fractionation and characterized by carboxymethyl-cellulose column chromatography, DEAE-cellulose column chromatography, SDS-polyacrylamide gel electrophoresis, and cyanogen bromide peptide mapping. Proteoglycans will be examined after fractionation by ion exchange column chromatography and gel filtration. We will also investigate the RNA metabolism in corneas. Total cellular RNA will be extracted from corneal stromal cell cultures and from individual corneal tissues and quantitated. Messenger RNA will be isolated by oligo(dT)-cellulose column chromatography. The activities of poly(A)-mRNAs will be examined in a cell-free translation system. Results obtained from pathologic samples will be compared with those obtained from normal controls. It is our hope to understand the connective tissue synthesis at a molecular level and to define specific biochemical abnormalities and mechanisms associated with each corneal disease. Our eventual goal is to apply the information acquired to the clinical care of these corneal diseases.